The other two were Israeli citizens: Gery Shalon, thought to be the mastermind, and his associate, Ziv Orenstein. They were arrested by Israeli police in 2015, and American prosecutors at the time were trying to extradite them to the United States.

The trio committed "the largest theft of customer data from a U.S. financial institution in history," according to the prosecutors.

The cyberattack on JPMorgan allowed hackers to grab contact information for 76 million households and 7 million small businesses. That included names, addresses, phone numbers and email addresses, as well as what the bank called "internal JPMorgan Chase information relating to such users."

According to the office of Manhattan U.S. Attorney Preet Bharara, the bank hacks were done to abet their "securities market manipulation schemes."

The statement cited Aaron's role in "orchestrating a massive computer hack into U.S. financial institutions, brokerage firms, and financial news publishers and for his role in a multimillion-dollar stock manipulation scheme."

Once the campaign succeeded in raising a stock's price and trading volume, Aaron and other members of the conspiracy would sell their shares resulting in huge profits, the FBI said.

Several media outlets mistakenly reported rumors that the bank came under attack by Russia. However, federal prosecutors last year made clear the attack was perpetrated by three criminal hackers -- not elite Russian government spies.